For many years snub nose transition fittings were attached to a thermocouple probe casing or sheath by the process of brazing. However the brazing heat necessarily spread through the fitting and frequently damaged the contained thermocouple wires and/or their soldered connections. Accordingly, this process was superceded by use of a transition fitting having a short crimping nose which by use of a specialized tool was crimped or swaged onto the probe casing (U.S. Pat. No. 3,811,958 to Maurer). But this has not proven entirely satisfactory and brazing would still be preferred if the concurrent heat spread through the fitting could be avoided.